So I will start by saying, after having all this stuff apart on my bench for months, I think I finally found the golden ticket. Funny thing is, this ticket turned out not to be one thing, it turned out to be a combination of things that when addressed have shown some serious promise. Once I thought I had it figured out, I Basically took everything off the test (stage 3) car, made my modifications, and put them back on. First I was hoping for normal start up and idle, check, next I started with stock tune just watching the live HPFP data on the AP. Things seemed normal, so I loaded a more aggressive map, same, finally I loaded the map we ran the 572 on the dyno with the HPFP dropping under 1000 PSI and staying there and fuel trims maxing out from about 6 grand on. This map has been 100% unchanged since dyno day. After loading the map I did 2 pulls back to back and checked the log. HPFP and trims to my great happiness were both completely on track, HPFP took a dive for a small RPM range when boost got heavy but recovered almost instantly and held to redline, trims were negative. I followed this up by 2 more runs tonight with the same results. So what this pretty much tells me is, we made 572 with trims nearing max on 91, we now have negative trims, I have no idea what this combination of modifications will net as far as HP, but it seems 600 on good pump gas is not out of the question and with race gas, you are golden to at least that. I plan on offering the upgrade on the fuel system components on a mail in basis but not until I thoroughly test it on all fuels including E85, so it will be a little bit. Once I can get some miles on the parts and make sure they really are going to work for more then a few pulls I will be a little more confident, happy but skeptical at this point. This is the first step, but it is a very promising one. 6 months in and breaking down the N54 walls one by one.

After trying to figure it for a few months now, spending a LOT of time and finally getting something to work, I wont be releasing the actual specifics of what we are doing, but it has to do with increasing flow in a few different areas. Also the way I think we are going to work it is. There will be 2 options, you send us your pump (new or the one off your car) and a couple other fuel system components, we modify them and send them back. Cheapest route, or we buy new parts, modify them and send them to you. We haven't worked out pricing yet(its going to be reasonable), not going there until we prove the modifications with some miles and dyno time.

Your Walbro having that much trouble keeping the STFT/LTFT in check with 100% E85??

Yeah the hfpf is totally over taxed with 100% e85. I was making tons of power on relatively low boost and conservative advance but the hfpf kept hhiccupping around 4k rpm and would recover but the pressure drops were pretty drastic. We made 469/491 no meth on our first map 6 test and easily could have seen 500/520 type number on the stock turbos if the hfpf would have behaved. For now the plan is to lower the ethanol percentage to 60ish and stack it with meth. Once this upgraded hfpf comes out I will revisit 100% e85 and stage 2 turbos.

Yeah the hfpf is totally over taxed with 100% e85. I was making tons of power on relatively low boost and conservative advance but the hfpf kept hhiccupping around 4k rpm and would recover but the pressure drops were pretty drastic. We made 469/491 no meth on our first map 6 test and easily could have seen 500/520 type number on the stock turbos if the hfpf would have behaved. For now the plan is to lower the ethanol percentage to 60ish and stack it with meth. Once this upgraded hfpf comes out I will revisit 100% e85 and stage 2 turbos.

That's what my HPFP is also doing with E85 (well anything over E60 really), otherwise I'd be over the ~530 whp I'm seeing with the RBs now with E50. Walbro holding up real good though, so I really hope Tony will be able to make his design changes work

That's what my HPFP is also doing with E85 (well anything over E60 really)

I'd recommend that you try to see if you have old strict-pump gas data logs & try to compare them against new ones. Try to see if there's a noticeable (and consistent) difference between the fuel trims when you compare the old vs. new data. If there is a big difference, your HPFP might be on its way out.

I'd recommend that you try to see if you have old strict-pump gas data logs & try to compare them against new ones. Try to see if there's a noticeable (and consistent) difference between the fuel trims when you compare the old vs. new data. If there is a big difference, your HPFP might be on its way out.

Well, I've been running E30-E60 mixes for over a year now, so I don't have any old logs to compare to. Running 21 psi midrange and 17-18 top end on RBs is no problem for the HPFP as long as the mix doesn't go above ~E65. I never get any fuel codes (not even 2AAF) unless above E65 level.

My first HPFP went out 2 years ago, so I've been there as well. This one has about 25k miles on it. Anyway Dzenno has been looking at my latest logs as well, so I'm sure he'll spot any potential HPFP issues. But considering I'm putting down ~530 rwhp without meth, I think it's very plausible that the HPFP just isn't cutting it with straight E85